NOPR Collection:

Solid phase extraction and spectrophotometric determination of vanadium

2013-08-08T16:36:00Z

Title: Solid phase extraction and spectrophotometric determination of vanadium Authors: Zhang, Chengming; Hua, Qiufen; Gu, Kun; Yang, Guangyu; Yin, Jiayuan Abstract: A sensitive, selective and rapid method has been developed for the determination μg/L level of vanadium based on the rapid reaction of V(V) with 2-(2-quinolylazo)-5-dimethylaminophenol (QADMAP) and the solid phase extraction of the colored chelate with C₁₈ cartridge. QADMAP reacts with V(V) in the presence of citric acid-sodium hydroxide buffer solution (pH=3.5) and cetyl trimethylammonium bromide (CTMAB) medium to form a violet chelate of a molar ratio 1:2 (V:QADMAP). This chelate is enriched by solid phase extraction with C₁₈ cartridge and the enrichment factor of 50 was obtained by elution of the chelate from the cartridge with ethanol. Molar absorptivity of the chelate has been found to be 1.22×10⁵ L.mol^-1.cm^-1 at 585 nm. Beer's law is obeyed in the range of 0.01-0.6 μg/mL. The detection limit is 0.04 μg/L in original samples. This method has also been applied to the determination of V(V) in water and biological samples. The relative standard deviations are 1.8-2.5%, and the recoveries are 96-103%. Page(s): 2590-2594

Synthesis, ion-exchange and physicochemical studies on a polystyrene cerium(IV) phosphate hybrid fibrous ion exchanger

2013-08-11T16:35:06Z

Title: Synthesis, ion-exchange and physicochemical studies on a polystyrene cerium(IV) phosphate hybrid fibrous ion exchanger Authors: Varshney, KG; Tayal, N; Gupta, Puja; Agrawal, Arun; Drabik, M Abstract: Polystyrene based cerium(IV) phosphate (PStCeP) has been synthesized as a new phase of fibrous ion exchanger. It has been characterized using IR, TGA, XRD and SEM studies in addition to its ion-exchange capacity, elution, pH titration and distribution behaviour. The Na⁺ ion exchange capacity is found to be 2.95 meq/dry g. A comparison of PStCeP with other materials of this class such as acrylonitrile cerium(IV) phosphate (ANCeP), acrylamide cerium(IV) phosphate (AACeP) and polystyrene thorium(IV) phosphate (PStThP), have also been discussed. Page(s): 2586-2589

Spectrophotometric studies on the simultaneous determination of cadmium and lead by using artificial neural network

2013-08-08T16:35:52Z

Title: Spectrophotometric studies on the simultaneous determination of cadmium and lead by using artificial neural network Authors: Sohrabi, M R; Abdolmaleki, P; Davallo, M; Rabbani, M; Ebrahimi, R Abstract: Simultaneous spectrophotometric determination of cadmium(II) and lead(II) based on formation of their complexes with ethylendiaminetetraacetic acid (EOTA) has been proposed. An artificial neural network (ANN) model has been used to analyze the mixture spectra. Absorption spectra of various concentrations of Cd-EOTA and Pb-EDTA solutions in the wavelength between190-290 nm have been recorded, and the spectral data and concentration used as input and output for the ANN, respectively. In this study, an ANN consisting of three layers of nodes has been trained by applying a back-propagation learning rule. Sigmoid transfer functions have been used in the hidden and the output layers to facilitate non-linear calibration. The root mean square error for cadmium and lead are 0.048 and 0.023, respectively. Page(s): 2582-2585

Synthesis and characterization of tridentate Schiff's base derived from 5-(2'-thiazolylazo) salicylaldehyde and p-methoxy aniline and their Mn(II), Co(II), Ni(II), Cu(n), Zn(II), Cd(II) and Hg(II) complexes

2013-08-11T16:35:00Z

Title: Synthesis and characterization of tridentate Schiff's base derived from 5-(2'-thiazolylazo) salicylaldehyde and p-methoxy aniline and their Mn(II), Co(II), Ni(II), Cu(n), Zn(II), Cd(II) and Hg(II) complexes Authors: Hankare, P P; Gavali, LV; Bhusea, V M; Delekar, S D; Rokade, R S Abstract: A series of new complexes involving Mn(II), Co(II), Ni(II),Cu(II), 2n(II), Cd(II) and Hg(II) ions and Schiffs base ligand obtained by condensation of 5-(2'-thiazolylazo) salicylaldehyde and p-methoxy aniline have been synthesized. The complexes are characterized by elemental analysis, magnetic susceptibility, molar conductance, IR, electronic spectra, ESR and thermal analysis (TGA). The ONN environment of the metal ion is realized in the complexes by involvement of the -N=N- group in coordination. The analysis of magnetic moment and electronic spectral data indicate tetrahedral geometry for the Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) complexes, while distorted tetrahedral geometry for the Cu(II) complex. Page(s): 2578-2581